Tuesday, December 20, 2016

This compressed view of the entire sky visible from Hawai'i by the Pan-STARRS1 Observatory is the result of half a million exposures, each about 45 seconds in length, taken over a period of 4 years. The shape comes from making a map of the celestial sphere, like a map of the Earth, but leaving out the southern quarter. The disk of the Milky Way looks like a yellow arc, and the dust lanes show up as reddish brown filaments. The background is made up of billions of faint stars and galaxies. If printed at full resolution, the image would be 1.5 miles long, and you would have to get close and squint to see the detail.
Danny Farrow, Pan-STARRS1 Science Consortium and Max Planck Institute for Extraterrestial Physics.Low Resolution (jpg)

The Pan-STARRS1 Observatory on Halealakala, Maui, opens at sunset to begin a night of mapping the sky.
Photo by Rob Ratkowski.Low Resolution (jpg)

Cambridge, MA - The
Pan-STARRS project at the University of Hawai'i Institute for Astronomy
(UH IfA) is publicly releasing the world's largest digital sky survey
today from the Space Telescope Science Institute (STScI) in Baltimore,
Md. The Harvard-Smithsonian Center for Astrophysics (CfA) is among the
partners who contributed to the Pan-STARRS1 Surveys.

"The Pan-STARRS1 Surveys allow anyone to access millions of images
and use the database and catalogs containing precision measurements of
billions of stars and galaxies," said Dr. Ken Chambers, Director of the
Pan-STARRS Observatories. "Pan-STARRS has made discoveries from Near
Earth Objects and Kuiper Belt Objects in the solar system to lonely
planets between the stars; it has mapped the dust in three dimensions in
our galaxy and found new streams of stars; and it has found new kinds
of exploding stars and distant quasars in the early universe."

"With this release we anticipate that scientists - as well as
students and even casual users - around the world will make many new
discoveries about the universe from the wealth of data collected by
Pan-STARRS," Chambers added.

The four years of data comprise 3 billion separate sources, including
stars, galaxies, and various other objects. The immense collection
contains 2 petabytes of data, which is equivalent to one billion
selfies, or one hundred times the total content of Wikipedia.

The first Panoramic Survey Telescope & Rapid Response System
(Pan-STARRS) observatory is a 1.8-meter telescope at the summit of
Haleakala, on Maui. In May 2010, it embarked on a digital sky survey of
the sky in visible and near infrared light. This was the first survey to
observe the entire sky visible from Hawaii multiple times in many
colors of light, with the goal of finding moving, transient, and
variable objects, including asteroids that could potentially threaten
the Earth. The survey took approximately four years to complete, and
scanned the sky 12 times in each of five filters.

"Achieving the high quality of the Pan-STARRS1 measurements and
maintaining it over such an enormous quantity of data was a unique
computational challenge and the results are a tribute to the dedicated
efforts of our small team of scientists at the UH IfA and our
collaborators who worked to process and calibrate the extraordinary
volume of raw image data," said Dr. Eugene Magnier, lead of the
Pan-STARRS Image Processing team.

A number of CfA scientists were involved in analyzing Pan-STARRS data
and extracting groundbreaking results. For example, Dr. Douglas
Finkbeiner and students Edward Schlafly and Gregory Green led the effort
to map the interstellar dust in the Milky Way in three dimensions. They
used the colors of nearly 1 billion stars, requiring photometric
calibration at a level unprecedented for ground-based surveys.

"The tiny particles in dust clouds make background stars fainter and
redder, for the same reason the sky turns red at sunset," said Dr.
Finkbeiner. "In order to measure the subtle color shifts, we must know
the brightnesses and colors of the stars at the percent level. With
vastly more data than any human could ever look at directly, this
required serious effort, and I'm proud of everyone who contributed."

"Pan-STARRS also has given us an unprecedented view of the dynamic
and transient nature of astronomical phenomena," said CfA astronomer Dr.
Edo Berger. "Our group discovered and studied new types of supernova
explosions and the disruptions of stars by supermassive black holes from
the Pan-STARRS data."

The Pan-STARRS1 Surveys program was undertaken by the PS1 Science
Consortium - a collaboration among 10 research institutions in four
countries with support from NASA and the National Science Foundation
(NSF). Consortium observations for the sky survey, mapping everything
visible from Hawaii, were completed in April 2014. This data is now
being released publicly.

"The cooperation between STScI and the Pan-STARRS team at the
University of Hawaii has been essential to ensuring that this initial
data release is successful," explained Dr. Marc Postman, Head of the
Community Missions office at STScI, and liaison between STScI and the
PS1 Consortium.

"STScI was a natural partner to host the Pan-STARRS
public archive given its extensive experience serving astronomy data to
the international community. In advance of the release of the Pan-STARRS
data, STScI staff helped perform checks of data quality, helped write
archive user documentation, tested and installed the local data storage
and database query system, and designed, built and deployed the
web-based user interfaces to the archive system."

The rollout is being done in two stages. Today's release is the
"Static Sky," which is the average of each of those individual epochs.
For every object, there's an average value for its position, its
brightness, and its colors. In 2017, the second set of data will be
released, providing a catalog that gives the information and images for
each individual epoch.

The Space Telescope Science Institute provides the storage hardware,
the computers that handle the database queries, and the user-friendly
interfaces to access the data.

The survey data resides in the Mikulski Archive for Space Telescopes
(MAST), which serves as NASA's repository for all of its optical and
ultraviolet-light observations, some of which date to the early 1970s.
It includes all of the observational data from such space astrophysics
missions as Hubble, Kepler, GALEX, and a wide variety of other
telescopes, as well as several all-sky surveys. Pan-STARRS marks the
nineteenth mission to be archived in MAST.

Headquartered
in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics
(CfA) is a joint collaboration between the Smithsonian Astrophysical
Observatory and the Harvard College Observatory. CfA scientists,
organized into six research divisions, study the origin, evolution and
ultimate fate of the universe.

For more information, contact:Christine PulliamMedia Relations ManagerHarvard-Smithsonian Center for Astrophysics617-495-7463cpulliam@cfa.harvard.edu